The digital age has brought people many types of electronic devices, such as notebook computers, personal digital assistants (PDAs), and so on. The manufactures of electronic devices are constantly searching for products that enable general consumers to stay informed all the time.
The portable electronic devices that are currently available in the market include PDAs, portable computers, mobile phones, and so on. As these portable electronic devices are all used for particular applications, their circuit designs are all for that specific application. For example, the PDA is to meet the needs of the user in the data usage; therefore, the PDA provides strong functions of for example scheduling, calculation, and data management. On the other hand, mobile phones are mainly for communication; therefore, the mobiles phones can communicate through the mobile communication network.
In addition to the above digital products, the global position system (GPS) technology is also widely used in position detection and vehicle navigation.